This is generally and specifically Reformed. Generally, they read the Reformed Confessions, the Bible, and sing the Psalms. including the chanted ones from Westminster Abbey. To their credit, they use music from the Anglican and Lutheran musical traditions. Theologically and worship-wise, an oasis in the American wasteland of Anabaptism, Pentecostalism, Warren-type mega Popish outfits, and the mainline carcasses of shallowness, impiety, and ignorance.
It's a site worth following.